Improvement in photographic-plate holders



S. L. BERGSTRESSER.

Photographic-Plate Holder.

No. l59,537. y y l PaemedFemmmm.

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*Ui I :l J 6 T U HZ- 1 J' UNITED STATES PATENT EEIcE.

STEWART L. BERGSTRESSER, OF LAURELTON, ASSIGNOR TO J. B. BERG- STRESSER, OF RENOVO, AND E. L. BERGSTRESSER, OF HUBLERSBURG,

PENNSYLVANIA.

IMPROVEMENT IN PHOTOGRAPHlC-PLATE HOLDERS.

Specification forming part of Letters Patent No. 159.537, dated February 9,1875; application iiled August 3, 1874.

To all whom it may concern:

Be it known that I, STEWART LEE BERG- STRESSER, of Laurelton, in the county of Union and State of Pennsylvania, have invented certain new and useful Improvements in Photographic Apparatus; and l do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it pertains to make and use it, reference being had to the accompanying drawings, which form part of this specification.

My invention relates to an improvement in photographic apparatus; and it consists in, tirst, forming a rim or flange around three sides of the plate-holder, so as to catch over the top and sides of the movable part of the camera, and thus exclude all light from the prepared sensitized plate; second, a flexible screen for excluding light from the sensitized plate while in the plate-holder, and being carried back and forth from the camera; third, guides placed in the plate-holder, whereby the holding devices for the plate can 'be adjusted up and down to suit dii'erent-sized plates; fourth, forming the plate-holder from a square box, which is open at its front only, so as to dispense with both the hinged door and slide heretofore used; fifth, a zinc box in which is placed the silver-box, so as to catch any silver that may be accidentally spilled from the silver-box, and which box can be adjusted up and down in the plate-holder at will sixth,

the arrangement and combination of devices which will be more fully describedr hereafter.

The accompanying drawings represent my invention.

The plate-holder consists of a fiat square box of suitable depth, which has a ilange or rim, j, formed around three of its sides, which rim tits over the top and sides of the rear end of the camera, and thus eii'ectually prevents the entrance of a single ray of light to the plate. This box is open at its front side only1 where the plate is inserted, and this opening is closed by means of a flexible screen, l, which has its ends connected together by two belts,

the drippings of silver.

n, which pass around suitable rollers m, placed at each side of the box. By means of this screen the plate-holder is kept closed while carrying the plate back and forth from thel camera, and I am enabled to dispense with both the hinged door and slide heretofore used. This screen may be made of any suitable material, and made to pass around rollers, as shown, or simply to operate in ways or guides prepared for it. To the back of the plateholder are secured the two ways or guides l, upon which the devices for supporting the prepared plate in position can be adjusted up and down, the devices having suitable catches, which catch behind the guides l. By slipping the devices up or down to the openings 2, cut in. the inner sides ot' the guides, they can be readily removed from and inserted into position. The lower device consists of a silverbox, 3, of any suitable construction, in which the lower cud of the plate rests, so as to catch This silver-box is placed in a somewhat larger box, 4L, made of zinc, and lined with blotting-paper, or other absorbent material, which catches any silver that may be accidentally spilled from the silver-box. This box has a slot cut in its upper edge, through which passes a set-screw, by means oi' which it can be adjusted up and down at will. The upper device, 5, is provided with a sliding bolt, 6, which has suitable catches 7, for catching over the top of the plate, and holding it in position, and a spring, 8, for throwing the bolt up when released. Back of the glass is placed a spring absorbent pad or cushion, 9, which keeps the plate pressed outward, so as to keep it from moving about.

It desired, the device 5 can be operated by a screw instead of as described.

Having thus described my invention, I claiml. A plate-holder having a rim or ilange formed around its edges, so'as to catch over the rear end of the camera, and prevent the admission of light to the plate, substantially as specicd.

screen and rollers7 around which the screen passes. substantially as set forth.

7. The spring absorbent pad 9, substantially as specied.

In testimony that I claim the foregoing I have hereunto set my hand this 31st day of July, 1874.

S. L. BERGSTRESSER.

Witnesses F. A. LEHMANN, FRANK CLAUDY. 

